Green drivers must avoid red mist

3 November 2008

Traffic on the M1If you’re interested in greener driving, you’ve probably encountered more than one list of the things you should do to cut fuel consumption. These usually contain sound advice: drive smoothly, accelerate gently, maintain correct tyre pressures, remove unused roof-racks, remove needless weight from the boot, use the aircon sparingly, don’t drive at speed with a window open, etc, etc.

The hardest tip to follow is the one that’s most obvious and most effective at reducing fuel consumption: drive more slowly.

Whatever make of car you drive, and however smoothly you pilot it, cutting your speed will dramatically cut your fuel consumption, particularly on faster roads. This is because the fuel being spent pushing the car through the air increases with the square of speed. If you drive a large, boxy car where drag is a big factor, travelling at 100mph can use as much as four times the fuel you would use to cover the same distance at 50mph.

We are not suggesting that you should drive at 30mph on the motorway – it’s not safe, and you could even be stopped by the police for obstruction.

However, there is a huge benefit to driving at the bottom end of the acceptable speed range on a given road. It will save you fuel, it will encourage others to save fuel, and amazingly enough you might actively reduce the fuel usage of even the most aggressive drivers on the road behind you.

Engineer William Beatty has published some interesting theories on how traffic jams form and how they dissipate. His informal research strongly suggests that drivers arriving more slowly than average at the site of a jam can help to remove the hold-up.

This is because a slower driver on a single-carriageway road or congested motorway will tend to accumulate an area of open road directly in front of them. This open space acts as a pulse of “anti-traffic”, an area with a lower density of cars than the rest of the road effectively “travelling” towards the jam at the same speed as you. When this area of emptiness arrives at the back of a queue of cars, it helps to give the jam the respite it needs to start to clear. If a number of drivers arrive in succession with a large gap in front of them, the build-up of cars can even clear completely.

As a slower driver you can, therefore, help to reduce the time that other drivers will spend in a traffic jam, where fuel economy usually plummets well below 10mpg. That is real green driving.

On a similar theme, Beatty explains that once in a jam, it’s vital to continue to behave meekly. If the cause of the jam is that two lanes are merging, don’t try to prevent other people merging ahead of you. Merging in “zipper” fashion – in turns, one from each lane – might seem like the best way to ease the congestion but in fact is still a slow way to defuse things. A greater volume of traffic will get through in a given time if the lanes take turns in larger lumps. So let two, three or even five cars jump in ahead of you. You can smile in the knowledge that you are helping to ease the blockage and will cut the fuel wasted in the jam as a whole.

You can even encourage this behaviour by leaving an extra-large gap ahead of you whenever you have to halt on a congested dual-carriageway.

The secret of green driving, therefore, has less to do with pumping up your tyres than it does with avoiding red mist. Leave in plenty of time. Drive more slowly. Look further ahead and adjust your speed to avoid braking. Don’t feel you are competing with other drivers. Accept that other cars will get ahead of you. Always let other drivers merge in front of you without complaint.

It may take some gritted teeth to drive in this way, but it will make a difference to the fuel consumption not just of your own car, but to the cars on the road around you

2 comments:

louiskart said...

Hmmm pretty cool really love the new look of it just hope to afford it more of it at acura tl accessories

Car Valeter said...

Its all a matter of getting used to it.. I have made it a point to drive economically over the last few months and you once you actually see the money you are saving, its an incredibly effective motive.

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